1. Field of the Invention
The present invention relates to a substrate handling apparatus, and more particularly to, an end effector on a substrate handling apparatus.
2. Prior Art
It is well known to use articulated arms to transport semiconductor wafers, plates and flat panel displays between cassettes, load locks, process modules and other work stations. Recent developments in the processing of semiconductors include the introduction of chemical metal polishing (CMP) and copper deposition whereby articulated arms can be exposed to abrasive or corrosive liquids and corrosive gasses. These fluids and gasses can infiltrate the clamping chuck of the end effector used to support the substrates and cause premature failure of mechanical and electrical components due to contamination and corrosion. U.S. Pat. No. 5,803,979 discloses a transport apparatus for semiconductor wafers that have been subject to chemical metal polishing (CMP). It discloses an end effector that can be easily removed for cleaning and an arm with catch chambers to collect materials drawn into the vacuum chuck. It also discloses cleaning fluid passed outwards through a vacuum passage in order to flush out materials from the end effector to the work area. A difficulty arises in that there must be a place within the work area to deposit the flushed materials from the end effector. Accordingly, there is a desire to provide a substrate transfer apparatus where cleaning fluid may be flushed through the vacuum passage in order to flush materials from the vacuum passage where the cleaning fluid remains internal to the substrate transfer apparatus.
In accordance with one embodiment of the present invention, a substrate handling end effector is provided. The substrate handling end effector has a vacuum chuck to support a semiconductor substrate thereon. A vacuum passage and a liquid passage are located in the vacuum chuck. The vacuum passage is adapted to be connected to a vacuum source and the liquid passage is adapted to be connected to a liquid source. The liquid passage is connected to the vacuum passage.
In accordance with another embodiment of the present invention, a semiconductor substrate transfer apparatus is provided. The semiconductor substrate transfer apparatus has a drive and an arm connected to the drive. A vacuum source and a liquid source are provided. An end effector is coupled to the arm and adapted to support a substrate. The end effector has a substrate support comprising a vacuum passage connected to the vacuum source, and a liquid passage connected to the vacuum passage and connectable to the liquid source. A liquid is adapted to be dispensed from the liquid passage to the vacuum passage.
In accordance with a method of the present invention, A method of cleaning a vacuum passage in a substrate supporting end effector is provided. A vacuum source is connected to a vacuum passage of a substrate support of the end effector. A source of liquid is then connected to a liquid passage of the substrate support. Liquid is transported from the liquid passage into and through the vacuum passage.